Fuel pump connector wiring diagram (Page 1/2) Csjag JAN 12, 03:27 PM On my 85 2M4 2.5L I think I reversed the polarity of the fuel pump when I changed it and as a result its running backward. I want to reverse the wires at the plug connector in the engine compartment so I don't have to drop the tank again. The connector has 3 wires, 1 black, 1 red and 1 brown with a white stripe. Can anyone tell me which wires to cross to reverse the polarity so the pump will run in the correct direction? Thanks phonedawgz JAN 12, 04:12 PM Can't be done. The grounds are common between the fuel gauge and the fuel pump. Tan/White - power to the pump Black or Black/White - Grounds for both pump and gauge Pink - Fuel Gauge Sender It might be also that the Black wire is grounded to the tank itself via the fuel sender. Csjag JAN 12, 05:43 PM Darn Darn Darn! Well at least I know how to drop the tank now. Thanks 1984_barn_find JUL 24, 03:01 AM So my problem is I bought an aftermarket fuel pump for my 1984 SE... turns out it did not come with a wiring connection... now I can't find a harness to fit and the OEM is completely different.. any ideas? phonedawgz JUL 24, 12:43 PM Take pics of the connector and post them. by 1984_barn_find JUL 25, 09:07 AM Never mind... Autozone had one on the shelf so I snagged it.. that's the good news... bad news is I now have fuel all the way to fuel injector but nothing coming out of it... I will research the forum for this issues... thanks phonedawgz JUL 25, 10:24 PM You need more than just fuel, you need fuel under pressure. The ECM fires the injector by grounding one of the wires. The other wire has +12 switched from the fuse box. So if the ECM isn't working it won't fire the injector. Also if the ECM isn't receiving ignition pulses it won't fire the injector. The most likely problem with an ECM is no power to the ECM. They do fail but not often. Is the ECM running the fuel pump for two seconds via the fuel pump relay when you first turn the key to on? It should. Does the ECM turn on the check engine light, key on engine off? it should. One of the more likely reasons your ECM isn't getting power is no power to the power distribution post below C500, or an ECM reset connector left unconnected. http://cliff.hostkansas.com...2012/fuselinks_1.jpg ChapsDp SEP 12, 09:18 PM Hello guys I need help with my 85v6 fiero. I’m not sure what happened to it but it seems like the fuel pump wiring got burn of cut, so I need to know how to connect the cables the right way, my fiero now only cranks but it won’t star please help. Mickey_Moose SEP 13, 09:41 AM Download a copy of the factory service manual for your car. It has step by steps procedure for testing and finding faults. Google search and you will find... GodSend SEP 13, 01:38 PM This is perfect timing as I have been trying to figure out a fuel issue on my 3800sc swap. Already dropped the tank once. Trying to avoid it again as well. Im not intending to hijack this thread, but all the information should be relevant to both of us. What is the expected behavior with the yellow fuel pump connector when probing? I have ground continuity on all 3 pins. Pin a should be ground, pin b is fuel gauge feed, and pin C is 12+ from a relay (actually from 203 pin L which is fed from the relay). Before I dropped the tank I had ground on both the Gound pin (A) and pin (C). I figured that the pump was shorted because I did not expect ground on the pin thats being fed the 12+, (Someone on facebook mentioned its supposed to be like that, but I have my doubts) . After a swapping the pump im still having issues. I can jump pin C with 12+ from the terminal block close to 500C and get 45+psi easily in 1-2 seconds to my rail, but I get sparks. If I use a 18ish gauge wire it heats up FAST, (exacly what I expect when wring a 12+ to ground, who hasent made that mistake?). With a heavier gauge wire its not as much heat. Im not sure if the heat is just from too much current for a smaller gauge or if its legit a wiring issue.